Often, during power up phase of a device or of an integrated circuit (e.g. with a system on chip, or a memory chip), a start up sequence is executed to initialize the device and its functions. For example, patent application US2003/0233534 discusses the start-up of a computer device. Often this configuration must be accomplished before internal non-volatile memory is powered up and is ready to supply configuration data and/or before a CPU is started. Therefore, the configuration data, which must be provided before the powering up of internal non-volatile memory and/or a CPU, is often provided directly to input pins of the device or of the integrated circuit.
According to road vehicle functional standard safety requirements (like, for example, ISO 26262), automotive safety-oriented devices or systems on chips must be put into a safe state in case of permanent or transient faults. The safe state, is for example, a reset state in which the device or system on chip can be optionally debugged. The devices or systems on chip may have a separate reset controller which may receive, at start up, specific configuration data.
However, when to devices, which have to fulfil the standard safety requirements, configuration data is provided via the input pins of the device of the package of the system on the chip, safety issues may arise when the input pins are, for example, not correctly connected to the printed circuit board or when, in the package of the system on the chip, bonding wires are not well connected. The same safety issues rise when input pins, or wires on the printed circuit board are connected to an incorrect logical value. In such cases incorrect configuration data may be received and the device, the system on the chip, or, for example, the reset controller does not correctly start up and may not end up in the (required) safe state. There is a need to detect whether the received configuration data is correct.